Apoptotic and antiproliferative properties of 3β‐hydroxy‐Δ5‐steroidal congeners from a partially purified column fraction of Dendronephthya gigantea against HL‐60 and MCF‐7 cancer cells

Abstract

Organisms belonging to the genus Dendronephthya are among a group of marine invertebrates that produce a variety of terpenoids with biofunctional properties. Many of these terpenoids have been proven effective as anticancer drugs. Here, we report the antiproliferative effect of 3β-hydroxy-Δ5-steroidal congeners against the proliferation of HL-60 human leukemia cells and MCF-7 human breast cancer cells. The sterol-rich fraction (DGEHF2-1) inhibited the growth of HL-60 and MCF-7 cells with IC values of 13.59 ± 1.40 and 29.41 ± 0.87 μg ml respectively. Treatment with DGEHF2-1 caused a dose-dependent increase in apoptotic body formation, DNA damage and the sub-G apoptotic cell population. Moreover, DGEHF2-1 downregulated the expression of Bcl-xL while upregulating Bax, caspase-9, and PARP cleavage in both HL-60 and MCF-7 cells. The steroid fraction was found to act via the mitochondria-mediated apoptosis pathway. Identification of the sterols was performed via gas chromatography-tandem mass spectrometry analysis. Studying the mechanism of the anticancer effect caused by these sterol derivatives could lead to the identification of other natural products with anticancer properties.

Fucoidan Purified from Sargassum polycystum Induces Apoptosis through Mitochondria-Mediated Pathway in HL-60 and MCF-7 Cells

“…Activation of Bax causes disruptions in the voltage-dependent anion channels in mitochondria releasing pro-apoptotic factors and cytochrome c that propagate apoptosis. Bcl-xL, which resides on the outer mitochondrial membrane, inhibits the activation of pro-apoptotic proteins such as Bax, thereby inhibiting the release of pro-apoptotic factors and cytochrome c [21]. In the present study, treatment of F5 increased the levels of Bax while reducing Bcl-xL.…”

“…Nuclear fragmentation and chromatin condensation of the cancer cells were evaluated by using the nuclear staining dye Hoechst 33342 (10 µg mL −1 ) and via the double staining method using acridine orange/ethidium bromide (100 µg mL −1 ). Experiments were carried out, according to [21]. Briefly, 24 h pre-seeded cells were treated with different concentrations of the samples and incubated for 24 h. The fluorescence dyes were then applied to the wells and incubated for 10 min.…”

“…The proportion of cells in the Sub-G 1 phase of the cell cycle, which indicate apoptotic hypodiploid cells were measured using flow cytometry. The experiments were carried out according to the method described by [21]. Briefly, cells (2 × 10 5 cells mL −1 ) were incubated with different concentrations of F5 for 24 h. The cells were then harvested, washed with PBS, and fixed in 70% ethanol followed by washing with EDTA (2 mM) in PBS.…”

“…The DNA damage caused by F5 was analyzed by evaluating the single-cell DNA damage (comet assay) and DNA laddering analysis. The alkaline comet assay was performed by using cells incubated with different concentrations of F5 for 24 h. Experiments were carried out according to the method described by [21]. For the DNA laddering analysis, the cells were incubated with samples for 24 h and harvested after PBS washing.…”

Antioxidant Potential of Sulfated Polysaccharides from Padina boryana; Protective Effect against Oxidative Stress in In Vitro and In Vivo Zebrafish Model

“…Following a 24 h incubation period, the cells were stained with cell permeable DNA dye Hoechst 33342 (10 µg/mL). Given 10 min incubation period, the cells were observed by a fluorescence microscope equipped with a CoolSNAP-Pro color digital camera (Olympus, Tokyo, Japan) [53,54].…”